Luke Skywalker's home planet of Tatooine now has three real-life rivals after astronomers discovered a trio of giant planets orbiting a pair of stellar 'twins' that resemble our sun.

The unusual twin stars, named HD 133121A and HD 133131B, were found to circle each other at an extremely close distance – just 33.5 billion miles apart.

This is around a third of the distance of other binary star systems, yet this close knit pair still manage to host three giant planets in orbit around them.

A pair of stellar twins similar to our sun have been discovered to have three giant planets in orbit around them (illustrated). The two stars orbit each other at a distance of 33.5 billion miles, or 360 Astronomical Units (AU), which is much closer than other binary stars

HD 133121A has two planets – one around 1.5 times the size of Jupiter and another half the size of Jupiter – both of which orbit it in an unusual eccentric elliptical way.

STRANGER THAN STAR WARS

When the science fiction hit Star Wars hit cinemas, the alien world of Tatooine with its two suns was a work of fiction.

But in recent years astronomers have discovered many planets in orbit around so-called 'binary stars'.

Perhaps the weirdest to be found, however, are planets that are scorched by three suns.

One found earlier this year, named HD 131399Ab, is one of the coldest of these triple star planets, but still has a temperature of 1,070°F (580°C).

It is four times the mass of Jupiter and sits 340 light years from Earth.

Its twin hosts a third planet that is 2.5 times the mass of Jupiter.

With two suns orbiting each other at such a close distance, the planets are likely to be scorched worlds.

Finding such large planets is also extremely rare but to make it even stranger, the gravity of the giant planets appear to have warped the solar system so it is misaligned and the smaller planets orbit at a tilt of up to 45 degrees to the plain of the stars.

Astronomers studying the strange solar system believe it could help to reveal how large planets like Jupiter can influence the structure of planetary systems.

Dr Johanna Teske, an astronomer at the Carnegie Institution for Science in Washington DC, said it could help to unravel why our solar system looks the say it does.

She said: 'We are trying to figure out if giant planets like Jupiter often have long and, or eccentric orbits.

'If this is the case, it would be an important clue to figuring out the process by which our Solar System formed, and might help us understand where habitable planets are likely to be found.'

The concept of planets with twin suns was first raised in the public consciousness with the original Star Wars film, where Luke Skywalker's home planet of Tatooine had been turned to a desert world by the heat of the suns.

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In the film Star Wars, Luke Skywalker's home planet of Tatooine is depicted as a desert world with two suns (pictured). The new star system, however, has three planets

STAR WARS-LIKE PLANETS AND MOONS

Planet or moon

Star Wars analog

Saturn's moon, Mimas

Death Star

Kepler-452

Coruscant

Uranus and Neptune

Bespin

Kepler-16b and Kepler 1647 b

Tatooine

OGLE-2005-BLG-390

Hoth

Kepler-22b

Kamino

Kepler-10b and Kepler-78b

Mustafar

While it is not yet possible to tell what the planets surrounding HD 133121A and HD 133121B are like, they are likely to have long hours of daylight and be hot.

Analysis of the stars, which were spotted using the Planet Finder Spectrograph on the Magellan Clay Telescope at the Las Campanas Observatory in Chile, has also shown that they are unusually low in metallic elements like iron.

Despite being old for stars, around 9.5 billion years old, they are mainly composed of hydrogen and helium.

Just six other metal-poor binary star systems with exoplanets have been found.

While the conditions of the planets orbiting HD 133121A and HD 133131B are not yet known, they could give astronomers new insights into how large planets like Jupiter influence their neighbouring planets (stock artist's impression of planet in a binary star system)

Dr Teske, whose findings are to be published in The Astronomical Journal, said that surprisingly the stars also seem to have slightly different chemical compositions, making them the stellar equivalent of fraternal twins.

She said one of the stars could have swallowed some baby planets early in its life, changing its composition slightly.

Alternatively the gravitational forces of the giant planets may have flung these smaller planets towards the star.

'The probability of finding a system with all these components was extremely small, so these results will serve as an important benchmark for understanding planet formation, especially in binary systems,' said Dr Teske.

THE REAL STAR WARS PLANETS

From the double sunsets on Tatooine to the frozen wasteland of Hoth, Star Wars is filled with a galaxy of fantastical planets.

While the words in Star Wars preceded Nasa's discovery of real planets outside our solar system, it appears in some cases fiction isn't too far from the facts

'When we send our spacecraft into the solar system and point our telescopes beyond, we often see things that seem taken right out of the Star Wars universe,' Nasa recently wrote in a blog.

For instance, Saturn's moon, Mimas, has become known as the 'Death Star' moon because of how its 80-mile wide Herschel crater creates a resemblance to the Imperial battle station.

Mimas was first spotted by Nasa in images taken by the Pioneer 11 when it flew by Saturn in 1979.

This was only two years after the first Star Wars came out - so that film's iconic Death Star was very much in the public consciousness.

It has a crater known as Herschel that is 80 miles across - leaving a giant mark across a moon just 246 miles across.

Even more dramatically, the crater has five-mile high walls, and the deepest part of the crater is six miles deep.

If Mimas was scaled up to Earth-size proportions, the crater would leave a scar on this planet larger than Australia.

The Star Wars fiction world features a city occupying an entire planet, known as Coruscant. The gleaming towers of Coruscant in the film are supposed to represent the power and prosperity of Republic civilisation